- Yes
- No
S-76 carrying 8 rocket pods (source: Sikorsky Archives)
The Sikorsky S-67 Blackhawk (not to be confused with the Sikorsky UH-60 Black Hawk) was an attack helicopter privately developed by Sikorsky in the 1970s. It was fast, reaching over 300 km/h in level flight and breaking two world speed records. It was agile yet easy to control, thanks to advanced aerodynamics and flight control systems. It packed a huge punch, carrying 152 rockets or 16 TOW missiles along with two Sidewinders and an autocannon. It would be exciting to see this beast prowling the tree lines of War Thunder’s battlefields.
History and design
The S-67’s origins trace back to the US Army’s Advanced Aerial Fire Support System (AAFSS) program from 1964. Sikorsky offered the S-66, using the “rotorprop” design, which involved a tail rotor that could rotate 90˚ to serve as both a conventional tail rotor and a pusher prop. Ultimately, the US Army chose Lockheed’s design, which became the AH-56 Cheyenne. However, the Cheyenne program soon began to falter, and Sikorsky saw the chance and seized it.
In 1970, Sikorsky unveiled the S-67 Blackhawk high-speed attack helicopter. While inheriting some design elements from the S-66, the S-67 had both regular and innovative features. The tail rotor was a conventional fixed design, perhaps because it was considered too risky after the failure of the S-66. However, it did have a large wing, at more than 8 meters from tip to tip, which provided extra lift at high speed and more space for weapons hardpoints. Two other unusual features were its all-moving tailplane and dive brakes on the wings. The horizontal “flying tail” provided extra manoeuvrability and helped the pilot better align the helicopter’s pitch when attacking targets. The airbrakes could be opened or closed in 3 seconds, and the additional drag reportedly increased time on target by 30% and increased dive angle by 38%, along with providing a smaller turn radius and improved firing accuracy. The S-67 also had a stability augmentation system (SAS) and a feel augmentation system (FAS) to improve handling. The helicopter was powered by two General Electric T58-GE-5 turboshafts with 1500 hp each, though more powerful engines could also be installed. It could reach over 310 km/h in level flight and 370 km/h in a dive. The front main gear could be retracted while the tail wheel could not.
The S-67 could carry an impressive array of weapons too. A TAT 140 turret is installed under the cockpit, capable of mounting 30 or 20 mm autocannons or a 40 mm grenade launcher. It had 4 underwing hardpoints (the production version was allegedly meant to have 6 underwing hardpoints, which is shown in some artists’ illustrations), capable of carrying 152 FFAR rockets in 8 pods (single pods on the outer pylons and triplet pods on the inner pylons) or 16 TOW missiles in 4 pods. Additionally, two Sidewinder missiles could be mounted on the wingtips (based on the period, most likely AIM-9B, D or E). Sources mention that night vision equipment was installed, but it’s unclear whether these included thermal sights. Even more interestingly, the S-67 could serve as a troop carrier. Initially, it could carry 15 troops in the upper level of a two-deck rear compartment, with the lower level containing fuel and ammunition, while later on it was installed with a thermally and acoustically insulated compartment for 6 troops. Unfortunately, no sources talk about it carrying countermeasures, perhaps due to its status as a prototype.
The S-67 made its first flight on 20 August 1970. In December of the same year, it set two speed records: 348.97 km/h over a 3 km course and 355.48 km/h over a 15/25 km course. The S-67 was evaluated against the Bell 309 KingCobra and the AH-56, but ultimately none of them were chosen for production. The Army eventually initiated the Advanced Attack Helicopter program, which cumulated in the AH-64. The S-67 continued to undergo further testing and modification. In early 1974, it was fitted with an experimental variable pitch ducted fan in place of the conventional tail rotor.
On 1 September 1974, the sole prototype of the S-67 crashed during aerobatic demonstrations at the Farnborough Airshow. The co-pilot was killed in the crash while the commander (allegedly Kurt Cannon, the pilot who flew the S-67 in one of its record-breaking flights) died from injuries 9 days later. Investigations concluded that the commander had misjudged the entry conditions for a low-altitude roll and did not have enough altitude to recover. All work on the S-67 ceased after the crash.
Specifications
Crew: 2
Empty weight: 5,676 kg
Gross weight (crew + 45 mins fuel): 6,350 kg
MTOW: 10,002 kg
Engines: 2 x T58-GE-5 turboshafts with 1,500 hp each
Max level speed: about 310 km/h
Service ceiling: 5,180 m
Climb rate: 12 m/s
Armament:
- Turret with 30/20 mm cannon or 40 mm grenade launcher,
- Four underwing hardpoints: 152 rockets (2.75 inch FFAR), 16 TOW missiles
- Two wingtip hardpoints: 2 Sidewinder missiles (source dispute: several sources, based on historical imagery, say it carried 2 Sidewinders on wingtips; Sikorsky Archives says it could carry 4 without specifying placement; some just mention the Sidewinder capability without elaboration; others, including all official evaluation documents, make no mention of Sidewinder capability at all)
More pictures
S-67 with Sidewinders and TOWs (source: Janes)
Frontal image of S-67 carrying Sidewinders and TOWs (source: AirVectors)
S-67 with air brakes deployed (source: Sikorsky Archives)
S-67 landing (source: Wikimedia Commons)
S-67 with ducted fan modification (source: Janes)
Place in game
The main selling points of the S-67 are its flight performance and armament. Despite looking large and unwieldy, its statistics rival or even exceed that of advanced light helicopters, and pilots have described it as being very manoeuvrable. These characteristics will help it quickly enter and exit battle zones or doge enemy attacks. The 16 TOW missiles allow pilots to stay in the fight longer without having to frequently resupply, and the Sidewinders, while being early models, can still surprise inattentive enemy jets. However, survivability is a major downside of the S-67, being large and probably lacking countermeasures, RWR, or armour. Weighing it against other helicopters in game, I believe it should not be placed above 9.7, perhaps placing it at 9.3 if it does not have thermal sights.
Sources
- “Jane’s All the World’s Aircraft 1974-75” by John W.R. Taylor
- “The Illustrated Encyclopedia of Helicopters” by Giorgio Apostolo
- Sikorsky S-67 Blackhawk – Igor I Sikorsky Historical Archives
- “The Original Blackhawk: the Sikorsky S-67” by Bob Petite
- “X-Gunships: Cheyenne, Blackhawk, & Comanche” by Greg Goebel
- Attack Helicopter Evaluation, Blackhawk S-67 Helicopter (AD0771161)
- The Evolution of the Advanced Attack Helicopter (ADB006756)
- Historic U.S. Army Helicopters
- Sikorsky S-67 Blackhawk N671SA: Report on the Accident at Farnborough, Hampshire, England on 1 September 1974
- https://web.archive.org/web/20071011105403/http://records.fai.org/documents.asp?from=rotorcraft&id=9965
- https://web.archive.org/web/20070927002045/http://records.fai.org/documents.asp?from=rotorcraft&id=9962